A pyrotechnic initiator or ignitor, for example, for activating an air bag inflator, is described in the European patent document EP 609 605 A1. In FIG. 4 of that publication an ignition bridge has been illustrated to which a pyrotechnic material is applied by a printing process or by painting. The pyrotechnic material is designed to react with a release of sufficient energy to cause an air bag to expand. The pyrotechnic material specifically named in this publication is lead styphnate.
The advantage of the use of a pyrotechnic material on an igniting bridge is that the energy released is greater than the electrical energy supplied. With the aid of this additional energy, a space between the bridge and the ignited material can be jumped with ease.
It is, however, a disadvantage that such an organic material, as has been provided in EP 609 605 A1, is not mechanically and thermically stable under a variety of circumstances and the contact between the printed layer and the ignition bridge cannot always be reliably ensured.